Abstract
A compact ultra-wideband (UWB) microstrip-fed planar monopole antenna with the band-notched characteristic is presented. This antenna comprises an annular-shape radiating element and a tuning stub which is inserted into the annular structure to obtain the band-notched characteristic. The notch frequency can be easily adjusted from 5 to 6.3 GHz by tuning the length of the stub. The VSWR characteristic from (3–24 GHz) and quasi omni-directional radiation pattern is observed. The proposed antenna is suitable for all UWB communication applications and prevents interference with the WLAN systems.